Size of the moving window. This is the number of observations used for
calculating the statistic.

min_periods : int, default None

Minimum number of observations in window required to have a value
(otherwise result is NA).

freq : string or DateOffset object, optional (default None)

Frequency to conform the data to before computing the statistic. Specified
as a frequency string or DateOffset object.

center : boolean, default False

Set the labels at the center of the window.

how : string, default ‘None’

Method for down- or re-sampling

pairwise : bool, default False

If False then only matching columns between arg1 and arg2 will be used and
the output will be a DataFrame.
If True then all pairwise combinations will be calculated and the output
will be a Panel in the case of DataFrame inputs. In the case of missing
elements, only complete pairwise observations will be used.

Returns :

y : type depends on inputs

DataFrame / DataFrame -> DataFrame (matches on columns) or Panel (pairwise)
DataFrame / Series -> Computes result for each column
Series / Series -> Series

Notes

By default, the result is set to the right edge of the window. This can be
changed to the center of the window by setting center=True.

The freq keyword is used to conform time series data to a specified
frequency by resampling the data. This is done with the default parameters
of resample() (i.e. using the mean).